1930s semi-detached extensions in Westminster

Which postcode districts around Westminster do we cover for 1930s semi project work?

Every Westminster postcode district we draw in, the stock that dominates it and the authority that validates a 1930s semi project there. Westminster fees below are the statutory England rates for 2026, not 1930s semi project estimates.

What changes about a 1930s semi project in each part of Westminster?

Roof pitch, wall build-up and plot depth change every few Westminster streets, and each one changes what a 1930s semi project can achieve at that address.

• Paddington (W2) — 1930s semi project work in Paddington means regency terraces, modern apartments. Paddington is Regency and Victorian terraces, canal-side regen. Westminster City Council decides the Paddington application, and Paddington Basin anchors the Paddington location plan.
• Victoria (SW1E, SW1W) — a 1930s semi project in Victoria starts from regency terraces, post-war flats, and Victoria reads as Regency terraces, mixed-use. in SW1E. Westminster City Council assesses Victoria 1930s semi projects against its own Victoria character guidance, and the location plan we draw for Victoria references Victoria Station.
• Westbourne Green (W2, W9) — Victorian terraces and mansion blocks defines Westbourne Green, where victorian terraces, mansion blocks set what a 1930s semi project can do. Any Westbourne Green 1930s semi project is validated by Westminster City Council, with Royal Oak the usual Westbourne Green reference point on the site plan.
• Maida Vale (W9) — a 1930s semi project in Maida Vale starts from edwardian mansion blocks, victorian villas, and Maida Vale reads as Edwardian mansion blocks, canal-side. in W9. Westminster City Council assesses Maida Vale 1930s semi projects against its own Maida Vale character guidance, and the location plan we draw for Maida Vale references Little Venice.
• Mayfair (W1J, W1K) — 1930s semi project work in Mayfair means georgian townhouses, listed buildings. Mayfair is Georgian listed townhouses, luxury. Westminster City Council decides the Mayfair application, and Berkeley Square anchors the Mayfair location plan.
• Belgravia (SW1X, SW1W) — 1930s semi project work in Belgravia means regency stucco terraces, listed buildings. Belgravia is white stucco Regency terraces. Westminster City Council decides the Belgravia application, and Eaton Square anchors the Belgravia location plan.
• Marylebone (W1U, W1G, W1H) — 1930s semi project work in Marylebone means georgian terraces, edwardian mansion blocks. Marylebone is Georgian and Victorian terraces, mansion blocks. Westminster City Council decides the Marylebone application, and Marylebone High Street anchors the Marylebone location plan.

How do conservation areas and Article 4 affect a 1930s semi project in Westminster?

Westminster conservation designations: there are 56 across Westminster City Council, Pimlico, Soho, Covent Garden among them. Designation costs a Westminster owner the permitted-development route: a 1930s semi project then needs a £548 householder application over 8 weeks, in place of the £249 prior approval route that takes 6 weeks. Covent Garden is the Westminster designation that most often changes a 1930s semi project design.

Westminster and Article 4: Multiple Article 4 Directions — office-to-residential restrictions, HMO conversions, retail to residential in shopping zones. A 1930s semi project planned at a NW8 address is checked against that direction first; Westminster City Council publishes the Westminster extent, and the NW8 line rarely follows the Westminster boundary you would expect.

Digging below a Westminster property: Westminster basement policy restricts to single-storey, typically under 50% of rear garden footprint; lightwells and rooflights strictly controlled in conservation areas. Where a 1930s semi project in Westminster involves excavation that is read beside the Party Wall etc. Act 1996, which needs two months notice for a Westminster dig within 3 m of a neighbour, and Westminster City Council expects the NW8 ground conditions addressed in the application.

Westminster housing stock: Grand Georgian and Regency terraces in Belgravia and Pimlico; Victorian and Edwardian mansion blocks; heritage-rich townhouses throughout; very high listed building density. Heritage-first planning approach; listed buildings on almost every street; basement and rear extension policies particularly strict. Read that before choosing a 1930s semi project route in Westminster — construction, not postcode, sets what is achievable.

What happens if a Westminster property sits on a boundary?

• Kensington and Chelsea — adjoining Westminster, with 38 conservation areas centred on SW1. A 1930s semi project on the far side of the Westminster line is determined by RBKC Planning, so the Westminster quote for 1930s semi projects is checked against Kensington and Chelsea guidance before it is issued.
• Wandsworth — cross the Westminster boundary and Wandsworth Council takes the 1930s semi project instead, applying 45 conservation areas of its own around SW8. We re-price 1930s semi projects at the Westminster edge because Wandsworth policy and Westminster policy rarely align on 1930s semi project depth.
• Lambeth — cross the Westminster boundary and Lambeth Council takes the 1930s semi project instead, applying 64 conservation areas of its own around SE1. We re-price 1930s semi projects at the Westminster edge because Lambeth policy and Westminster policy rarely align on 1930s semi project depth.
• City of London — adjoining Westminster, with 27 conservation areas centred on EC1. A 1930s semi project on the far side of the Westminster line is determined by City of London Corporation, so the Westminster quote for 1930s semi projects is checked against City of London guidance before it is issued.

Sources for this Westminster 1930s semi project page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.